In this year, we completed three major sub-projects. First, we employed glutamate-sensitive sensors coupled with high-speed amperometry to evaluate rapid changes in glutamate following exposure to cocaine and nicotine. Second, we employed glucose-sensitive sensors coupled with high-speed amperometry to evaluate rapid fluctuations in brain glucose levels following exposure to natural stimuli and cocaine. Finally, we conducted a study, in which we examined fliuctuations in brain glucose and glutamate levels during natural drinking behavior.